Reverse Gearbox

[Doc Sprocket]

only problem is its also a ragb, unless he is using a mower engine...... not sure how much power it can handle.

That's not really a problem. You would mount the engine longitudinally (shaft pointing forward or back, not to one side like normal), and mount your gearbox on its side , so that the input shaft is oriented like the engine's crankshaft, and the output shaft is off to the left like normal. In fact, you could even modify a clutch to use a U-joint or flex coupler to directly attach the crankshaft to the gearbox input shaft, and eliminate a chain run!

I've thought about this a lot, in relation to a kart project I designed using a very similar gearbox.

With regards to the power handling issue, if the input is not under heavy reduction, I'm sure it would be fine. Steel case, too! Mine's only aluminum!

 

[r97]

yea i suppose that would work, be a pain to re-orientate the engine unless he is building a kart, might be easier on most peoples karts, but mine......

 

[r97]

my idea just got cheaper if your still interested, i may build one for the fun of building it!
http://cgi.ebay.com/Boston-58T-Spur-Gear-/300446988111?pt=LH_DefaultDomain_0&hash=item45f409374f#ht_500wt_922

 

[Stratus]

Well i just though I would need it becuase I use it a lot on my fourwheeler.

 

[Stratus]

my idea just got cheaper if your still interested, i may build one for the fun of building it!
http://cgi.ebay.com/Boston-58T-Spur-Gear-/300446988111?pt=LH_DefaultDomain_0&hash=item45f409374f#ht_500wt_922

I would like to know this idea please

 

[r97]

only way i can think a twisted belt would work is with a really long, not too wide, v belt with a lot of idlers. tensioning wouldn't be easy. my idea, i think is simple, and affective, might be cost more than the one on ebay, but you get to make it which means you know its good quality, and you can fix it with your eyes closed! its this except in an oil bath, and replacing one of the chain/sprocket combos, with two gears, if you use t as reverse it also almost eliminates the problem of not being able to shift on the go because you would be stopped, for the most part i don't think reverse is a necessity(unless you have a big kart), but its a fun project, and fun to have.


p.s. i'm not sure if the $10 one is what your looking for

this is my idea

 

[Stratus]

The person that made that gearbox has skill and money I have some skill but I have no money, but I will look into it, unless theres another way. How about an electric motor? or just less gears, and what is that gear from ebay for, r97?

 

[Stratus]

Could anyone explain the gearbox that was made?

 

[redsox985]

The original creator! No, if you search 2 speed DIY gear box, he links you to his webpage with a long written explanation of how he made it and how it works. It's still beyond me, although I never read into it that much.

 

[r97]

its actually really simple! the gears i pionted out were shone becase including those into the gear box would make it a forward reverse box. as we all know the direction of rotation is NOT changed with chain drive, where as it is reveresed with gear drive. his gear box could prob be made very affordable. you have an input js with a simple synchro-mesh(in this case a small 4 bolt doulbe hub pic1) that is FIXED to the input js, this synchro-mesh slides from left to right on the input js, this left to rght motion is controlled by the gear selector. on one side of the synchro-mesh assemblie is a sprocket which is on bearings, so it does not spin with the js, on the other side of the assemblie is a gear on bearings. both the sprocket and the gear would have about 8 holes drilled in them. the sprocket is connected (by roller chain) to a second sprocket fixed on the output js. the first gear meshes with a second gear fixed on the output js. so selector moves to one side and the studs (bolts without threads) move into the holes on either the gears or the sprockets selecting forward or reverse. few tiny deatials were left out, but they should be obvious,

http://www.diygokarts.com/vb/showthread.php?t=8890&highlight=speed+manual

http://www.thepixelpump.com/widdershins/how-to-2speed-transmission.php

EDIT: sry, but either i spelled everything right, or spell check is down

 

[Doc Sprocket]

FWIW, I repaired a neighbour's rototiller a few months back, and it's drive system was interesting. Truthfully, it wouldn't work well on a kart, but the concept was interesting. The engine was on a pivoting mount, connected to a large handle. On the output shaft of the engine was a pulley with a normal groove, and a large flat area with a heavy rubber covering. A belt connected the pulley to the drive system, which in Neutral was slack. Moving the lever into forward gear shifted the engine such that the belt would tighten. So far, so good. Here's the interesting bit- Moving the lever into Reverse would shift the engine the other way, bringing the pulley wheel into contact with a wheel also connected to the drive, which of course, would counterrotate and drive the tiller in reverse.

This would require some adaptation to be functional on a kart, but could be done. On the other hand, I really thought I'd miss reverse... And I don't.

 

[r97]

yea i'm fine without it, but i still like myself a project.

 

[Stratus]

How many gears do you think i will need? and where would i put them in the box?

 

[r97]

to make a reverse box? just use the same blue prints from the link on the thread i gave you. instead of having two chain drives, have one chain drive, with one gear drive, also note one gear must be on bearings. please if you are going to build this (or anything), know exactly how its going to work. two gears as reverse, and two sprockets as forward.

 

[fowler]

what toystory said is how a grain auger works like i said but i can say from expirence that it is difficult to use as u have to stand next to the lever and realy slam it down to click it in

 

[r97]

i can see toy story idea being very good normally but if you have a decent sized kart that is stuck in slick mud........ still good for just having because you really like it though, and prob works good in a few other applications.